Britney Spears has sparked speculation she's engaged after she was spotted wearing a sparkling ring on her engagement finger.The Toxic singer was shopping in Beverly Hills, California on Tuesday (11Aug09) when the paparazzi photographed her wearing a dazzling jewel on her left hand. Spears, who divorced the father of her two children Kevin Federline in 2006, has recently been rumoured to be dating her longtime agent Jason Trawick. A day before she was snapped sporting the ring, the 27 year old cemented her place as a pop princess when she was honoured with the Ultimate Choice prize at the Teen Choice Awards in Los Angeles.